This research program seeks to define the means by which phagocytosis, its associated oxidative metabolism and enzyme release from cytoplasmic granules are regulated in the polymorphonuclear leukocyte. Specifically, the roles of oxygenated transformation products of arachidonic acid (prostaglandins, thromboxanes and hydroxylated, unsaturated fatty acids), calcium and cyclic nucleotides (cAMP and cGMP) will be examined. In pursuit of this goal we will: quantitate production of primary prostaglandins, thromboxane B2 and their metabolites and hydroxylated fatty acids; measure cyanide-resistant oxygen utilization, O2, and H2O2 production and hexosemonophosphate shunt activity; measure intracellular and total incubation cyclic AMP and cyclic GMP concentration: study the release of enzymes characteristic of specific and azurophil granules; and investigate 45Ca2 ion fluxes in exudate polymorphonuclear cells at rest, during phagocytosis and during treatment with a number of agents known to affect leukocyte function, (for example: ionophores, lectins, cytochalasins), or to inhibit cyclo-oxygenase of lipoxygenase, for example: indomethacin, benzydamine, ETA.